In connection with surgery for a number of diseases in the gastro-intestinal tract, one of the consequences in many cases is that the patient is left with an abdominal stoma, such as a colostomy, an ileostomy or a urostomy in the abdominal wall for the discharge of visceral contents. The discharge of visceral contents cannot be regulated at will. For that purpose, the user will have to rely on an appliance to collect the material emerging from such opening in a bag, which is later emptied and/or discarded at a suitable time.
An ostomy appliance may be in the form of a one-piece appliance for which a collecting bag for human body wastes is permanently, or fixedly, secured to an adhesive base plate for attachment to the human skin. Alternatively, the ostomy appliance may be a two-piece appliance comprising a base plate and a collecting bag which may be coupled to and uncoupled from each other through a coupling means. This has the effect that the base plate does not need to be separated from the skin of the user as often as exchange of the collecting bag requires. The base plate may need only to be changed every third or fourth day depending on the user, whereas the collecting bag may be changed more than once per day. Typically, it is desirable to need as few exchanges of the base plate as possible in order to reduce the risk of skin complications.
Collecting bags may be provided in different sizes depending on the desired use. For example, larger bags may be used at night, whereas smaller bags may be used when discretion is needed. In some situations—e.g. during exercise—the use of so-called stoma caps may be preferred. Stoma caps are small collecting bags just covering the base plate and the stoma. However, since the discharge from the stoma cannot be regulated at will, a user wearing a stoma cap may need a collecting volume of a size exceeding the volume of the cap.